Saturday, 25 April 2015

Random ramblings

Are my ramblings really random?

What does random, or randomness even mean? The wikipedia (pretty good at a lot of topics) describes randomness as a lack of pattern or predictability in events. That seems like a reasonable definition to me, or at least it did until I thought more about what that means.

There's something missing in that definition - a subject, to whom the randomness appears. What appears random to one person might not be to someone else. All the events we see around us were preceded by event chains, some of which we are aware but most of which we are not. Events that happen as a result of unknown causal chains can appear to us as random but they are not - they are merely unpredictable (by us) because we don't have the information or the capability to make the prediction.

The same wiki page goes on to discuss this a bit but then launches into a discussion of random vs pseudo-random numbers. Random numbers come from "really random" events, whereas pseudo-random numbers come from deterministic (but complicated) algorithms to produce a series of numbers that don't have any obvious pattern or predictability. Example: so-called random number generators in computers. They aren't random numbers, they are an entirely predictable sequence of numbers in a complicated pattern that looks random. It looks like there isn't a pattern. But there is.

So what's different between a "really random" number and a pseudo-random one? Maybe, there isn't a difference. Maybe "really random" just means that the patterns aren't perceivable by us, and the results aren't predictable by us. So actually they are really only pseudo-random. Everything that happens is caused be a preceding event chain (except perhaps for quantum events - and I'm not entirely convinced about that). Or in other words, nothing is really random - just playing out a complex pattern that isn't knowable by us.

Take quantum mechanics. The main view seems to be that quantum events (like atomic decay) are really truly random, in the sense that they really don't have a cause ("God playing dice" - an idea that Einstein was never happy with). "Real randomness" is entirely consistent with the idea of the Universe as a vast computer simulation, though. If the random numbers are determined outside the simulation, then events determined on the basis of those would appear truly acausal from within it.

That explanation doesn't mean that events within the universe are meaningless because they are un-caused though, far from it - something exists outside the simulation and the simulation is being run for a reason.

But true randomness and acausal quantum events aren't the only interpretation of the meaning of the equations of quantum physics. De Broglie-Bohm theorem is another interpretation that's completely consistent with experimental observations and does not require "really random" events, but does require non-local hidden variables that describe the way every particle in the universe is related to ever other. So it seems that if there is nothing that happens without a cause, we need to accept that everything is connected by some kind of mysterious and unmeasurable something that links everything in the universe together.

Connected by what? Qi? The Force? The Pilot Wave?

Both of these interpretations leave room for sources of magical power. In the "world as a simulation" model, events could be influenced from outside by dicking about with the random numbers that determine quantum events, a process that can cause coincidences and synchronicities to occur but cannot break physical laws. Presumably our programmers have their reasons for not interfering directly in the simulation. In the "interconnected world" model, events can be influenced from inside by manipulating the Qi, but again not in a way that can violate physical laws.

I don't think I believe in randomness anymore  :-)

1 comment:

  1. To clarify a point - a cause from outside the universe (like a pseudo-random number generated on the machine that runs our simulation) - really is the same thing as truly random when experienced from inside the universe. This is because the event does not depend on the state of anything else in the universe - it really is the same thing as Einstein's hypothetical roll of the dice. In fact, in this way of seeing things, the idea of God playing dice could be literally true.